When used as a defibrillator in a synchronized discharge application, a defibrillator/monitor must be able to detect the QRS complex and discharge within 60 milliseconds (ms). Since response to QRS detection and closing of the patient relays can take as much as 30 ms, a synchronous QRS detector must be able to detect with little delay.
When used as a patient monitor, the defibrillator/monitor must be able to accurately determine the patient's heart rate. More accuracy may be required in this application, but a greater time delay tn QRS detection is permissible.
For the foregoing reasons, there is a need for a QRS detector which is both highly accurate for determining a patient's heart rate, and has minimal delay for initiating a synchronous defibrillation discharge.